57 research outputs found

    Molecular basis of biocide resistance and susceptibility in bacteria

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    The molecular basis of biocide resistance and susceptibility in Serratia and mycobacteria was investigated using transposon mutagenesis approach. The killing and growth inhibitory effects of four biocides (triclosan, cetylpyridinium chloride, chlorhexidine diacetate and alkaline orf/io-phthalaldehyde) on Serratia marcescens Dbll, Mycobacterium smegmatis mc2155, M. chelonae type strain NCTC 946, M. abscessus type strain ATCC 19977, and Escherichia coli NCTC 1048 were studied using minimal inhibitory concentration determination, biocide killing, and potassium leakage tests. Transposon mutagenesis using a mariner system did not produce any M. smegmatis mc2155 mutants with altered biocide sensitivity. In contrast mutagenesis of S. marcescens Dbll using the mini-Tn5Km2 transposon system led to the isolation of 26 biocide mutants. Increased resistance, susceptibility and mixed biocide phenotypes were observed in the mutants. Alteration in antibiotic susceptibility was also noted. The locations of transposon insertion in all but two of the mutants were determined, and 14 putative genes coding for putative proteins with diverse functions were found to be disrupted. These functions included anabolism and catabolism, gene regulation, cell envelope biosynthesis, porin, energy production, and virulence. Two mutants, one deficient in the outer membrane protein A (OmpA), and another deficient in the nucleoid-associated protein (NdpA), were complemented. Complementation of the ndpA mutant which showed increased resistance to cetylpyridinium chloride and chlorhexidine diacetate, but was sensitive to triclosan, lead to restoration of the wild type phenotype. Complementation of the ompA mutant, which showed multiple sensitivity to chlorhexidine diacetate, triclosan, and or/Zio-phthalaldehyde however, did not restore the wild type phenotype. The cloned ompA gene was shown to be transcribed but not translated in the complemented mutant. In summary, the genetic basis for biocide resistance in S. marcescens Dbll is multi-factorial and encoded by several novel loci worthy of further study

    The global meningitis genome partnership.

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    Genomic surveillance of bacterial meningitis pathogens is essential for effective disease control globally, enabling identification of emerging and expanding strains and consequent public health interventions. While there has been a rise in the use of whole genome sequencing, this has been driven predominately by a subset of countries with adequate capacity and resources. Global capacity to participate in surveillance needs to be expanded, particularly in low and middle-income countries with high disease burdens. In light of this, the WHO-led collaboration, Defeating Meningitis by 2030 Global Roadmap, has called for the establishment of a Global Meningitis Genome Partnership that links resources for: N. meningitidis (Nm), S. pneumoniae (Sp), H. influenzae (Hi) and S. agalactiae (Sa) to improve worldwide co-ordination of strain identification and tracking. Existing platforms containing relevant genomes include: PubMLST: Nm (31,622), Sp (15,132), Hi (1935), Sa (9026); The Wellcome Sanger Institute: Nm (13,711), Sp (> 24,000), Sa (6200), Hi (1738); and BMGAP: Nm (8785), Hi (2030). A steering group is being established to coordinate the initiative and encourage high-quality data curation. Next steps include: developing guidelines on open-access sharing of genomic data; defining a core set of metadata; and facilitating development of user-friendly interfaces that represent publicly available data

    Insulin Knowledge, Handling, and Storage among Diabetic Pilgrims during the Hajj Mass Gathering

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    Background. Diabetes is one of the most common underlying health conditions among Hajj pilgrims. Many diabetics manage their condition using insulin, which requires appropriate storage conditions to maintain its stability and effectiveness. We aimed to investigate insulin knowledge, storage, and handling among diabetic pilgrims during Hajj to identify specific areas for improvement. Method. Adult diabetic pilgrims from 22 countries were interviewed using a structured questionnaire during the 2019 Hajj. Results. The study enrolled 277 diabetic pilgrims with a mean age of 58.4 years (SD=10.4, range: 20-83) and male : female ratio of 1.6 : 1. Most participants (86.4%) were literate and reported using insulin for a mean of 7.1 years (SD=5.3, range: 1-23). Over 95% of pilgrims brought their insulin with them from their country of origin, where they also received most of their insulin storage information, mainly from physicians (77.8%) and pharmacists (59.6%). Pilgrims’ knowledge regarding insulin storage was just above average (mean knowledge score=0.51; SD=0.23). Pilgrims who were literate and previously received education on insulin storage, those with a higher level of education, and those with a longer duration of insulin therapy, had significantly higher knowledge scores. Pilgrims’ storage and handling of their insulin during Hajj also varied depending on the stages of their pilgrimage journey. Conclusion. Inadequate knowledge and inappropriate practices regarding insulin handling and storage were identified among diabetic Hajj pilgrims, which could compromise the quality of insulin and lead to health hazards. Improving diabetic pilgrims’ knowledge of diabetes management, including insulin storage, will be beneficial during the pilgrimage and beyond
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